The German international got off to a bright start to the season with goals against Liverpool and Southampton in the league, but the goals and performances have dried up since then.
Wenger admitted Podolski's performances have been a 'bit less fresh', and believes that the physical intensity of the Premier League is problem.
"He started well but he works very hard, and in recent games he has been a bit less fresh," he told The Guardian.
"He's not used to working at that level of intensity because at Cologne he plays and he says: 'My friends,'" Wenger said, holding out his arms like a spectator. "So when you come to England, it's a shock.
"In England, you have [Wayne] Rooney, who works his socks off … you have everybody who works hard. There is no room for anybody to work less or you don't exist. It's quite interesting to analyse. For example, Saturday's game at Man United, where we were not very good, the physical intensity of the game was absolutely unbelievable. If you have one or two players who don't do that, you just don't exist at all."
The 63-year-old has no doubts that Podolski will eventually adapt at Arsenal though.
"Podolski will adapt, I don't worry for him. He has a very good spirit and he wants to do very well. Of course, because he tries to help the team, sometimes he does some work now but he will get used to it."
Wenger mentioned Robert Pires as an example of a player who also suffered the culture shock upon arrival at Arsenal, but later went on to cement himself in the club's history as one of their best ever players.The Arsenal boss related the story of how Pires had been stunned as he experienced his first match in the English top flight.
"It was at Sunderland," Wenger said, "and I put him on the bench. I said: 'Today, you will sit next to me.' At the time, you had Peter Reid [as the Sunderland manager] and after 20 minutes, they kicked us well. Robert said to me: 'Is it always like that?'"